Field of the Invention
The present invention relates to a water-in-oil emulsion solid cosmetic. More specifically, the present invention relates to a solid makeup cosmetic that has an improved feeling in use by stably incorporating a powder into an internal water phase and is excellent in stability particularly at high temperatures.
Description of the Related Art
Water-in-oil emulsion-type solid cosmetics are characterized by, for example, being excellent in water resistance as compared with oil-in-water emulsion-type, and being able to efficiently contain an emollient oil, an oil-soluble agent, an ultraviolet absorber, or the like, but may offer a poor refreshing feeling and stickiness or an oily feeling in use. Conventional water-in-oil emulsion solid cosmetics, particularly, makeup cosmetics, are generally produced by dispersing a hydrophobized powder such as a hydrophobized pigment into an oil phase and solidifying the oil phase with a solid wax or the like. Aggregation may, therefore, occur due to the adsorption of powder particles onto the wax. Further problems caused by this aggregate are poor spreadability upon application and reduced freshness. In addition, the hydrophobizing treatment of a powder such as a pigment reduces the oil absorption ability of the powder. Thus, makeup deterioration or damage caused by sebum is difficult to prevent sufficiently.
Patent literature 1 describes a cosmetic having an improved feeling in use such as a refreshing feeling and the absence of stickiness, the cosmetic stably containing 30% by weight or more of water in a water-in-oil-type solid cosmetic by combining (a) long-chain alkyl/polyoxyalkylene-comodified organosiloxane having an HLB value of 8 or lower and (b) an alkyl group-containing polyoxyalkylene-added nonionic surfactant having an HLB value of 12 or higher. The oil phase, however, contains a hydrophobized pigment powder as a pigment for a makeup cosmetic such as a foundation, an eyeshadow color, or a blusher (Examples 5 to 7), and a base cream and a lip color containing a pigment powder in a water phase have a powder content of 5% by weight at the most (Examples 4 and 8).
Patent literature 2 describes a water-in-oil solid emulsion cosmetic comprising an external oil phase solidified with a wax and/or a gelling agent and states that a cosmetic that has good spreadability upon application, fresh feeling and long-lasting property is obtained by incorporating a powder dispersant which stably disperses a powder in a water phase. The cosmetic specifically described in patent literature 2, however, contains only either one of the wax and the gelling agent, and lacks stability particularly at high temperatures.
In addition, the cosmetics described in patent literatures 1 and 2 each contain a large amount of cyclic silicone oil and therefore there are problems associated with feeling in use, such as poor spreadability and reduced refreshing feeling.